In the IIoT application, IoT Router is a key device for connecting devices and networks. Its stability and reliability directly affect the normal operation of the entire system. However, in actual use, IoT Router sometimes has problems connecting to the network. This not only affects the real-time and accuracy of data transmission but also may have a significant impact on the entire production process. This article will provide a detailed professional explanation on how to systematically troubleshoot when the IoT Router cannot connect to the internet.
I. Preliminary inspection and confirmation

1. Check the power supply and indicator light
   First, confirm whether the power supply of IoT Router is connected normally and whether the indicator light is on. If the power indicator is not on, it may be due to a loose plug, damaged cable or internal fault of router. At this time, check the power plug and power cord, and try to replace the power socket for testing.

2. Check the network connection
   Confirm whether the IoT Router is properly connected to external networks, including broadband access devices such as fiber optic modems and ADSL modems, as well as wired/wireless networks. Check whether the network cable is firmly plugged in, whether it is damaged and if the network interface works normally. If you are using a wireless network, check the wireless signal strength and SSID settings.

3. Check the router status
   To log in to the management interface of IoT Router, you usually access the router's IP address through a browser to view its running status and log information. This information can help us quickly locate the problem, such as WAN port status and IP address allocation.
   II. Conduct in-depth troubleshooting

4. Check the WAN port settings
   If the IoT Router cannot obtain an external network IP address, it may be due to incorrect settings for the WAN port. Check whether the connection type of WAN port, such as PPPoE, static IP and dynamic IP matches with actual network environment. Confirm that authentication information like user name and password is input correctly.

5. Check the DNS settings
   The DNS domain name system is a key service that converts domain names into IP addresses. If the DNS settings are incorrect or the DNS server is not responding, it will cause the IoT Router to be unable to access the Internet. Check whether the DNS settings of your router are correct, and try to change other available DNS servers for testing.

6. Check firewall and security settings
   IoT Router usually has built-in firewalls and security policies to protect network security. However, overly strict firewall settings may prevent normal network access. Check the firewall and security policy settings of your router to ensure that you have not mistakenly blocked necessary network access.

7. Check the physical environment
   The physical environment may also affect the network connection of IoT Router. Check whether there are interference sources such as microwave ovens and wireless phones around the router. These devices may interfere with wireless signals or cause network instability. In addition, it is necessary to check whether the router placement location has good ventilation and avoid performance degradation caused by overheating.

8. Try to restart the router
   Sometimes, a simple restart can solve the problem of the router not being able to connect to the network. Restarting the router can clear cache and temporary files, restoring network settings to their initial state. Before restarting, it is recommended to save the current network configuration and settings.
   III. Advanced fault troubleshooting

9. Use network diagnostic tools
   If the above steps fail to solve the problem, you can use a professional network diagnostic tool for further troubleshooting. These tools can provide in-depth analysis of network traffic, data packets and protocols to help us find potential network problems.

10. Contact technical support
    If the problem still cannot be solved, it is recommended to contact the technical support team of IoT Router or the manufacturer's customer service. They can provide professional technical support and solutions to help us quickly restore network connectivity.
    IV. Summary and Prevention

11. Regular maintenance and inspection
    Regular maintenance and inspection of the IoT Router is an important measure to prevent failures. including cleaning dust, checking network cable connections, updating firmware and software, etc. These measures can ensure the stability and reliability of routers.

12. Backup important data
    During the troubleshooting process, it may involve restarting or resetting the router. Therefore, before troubleshooting, it is necessary to back up important network configurations and data to prevent problems caused by data loss or configuration loss.

13. Pay attention to network security
    While troubleshooting, we should also pay attention to network security issues. Ensure that the security settings of your router are correct to avoid security issues such as hacking or virus infection.
    When the IoT Router cannot connect to the network, we should follow certain steps for troubleshooting. Starting from preliminary inspection and confirmation, gradually deepen into the advanced troubleshooting stage. By systematically troubleshooting and solving problems, we can ensure the stable operation of IoT Router and the normal operation of the entire industrial Internet of Things system.